Integrated TBC and cooling flow metering plate in turbine vane

Abstract

An integrated thermal barrier coating and cooling flow metering plate for a turbine vane are disclosed. On an existing vane design, the thickness of the thermal barrier coating is increased in order to provide more thermal protection around the vane material itself. The increased insulation around the vane allows the volume of cooling air flow to be reduced, while still maintaining the vane temperature within specification. The reduced cooling air flow is obtained by adding a flow metering plate at the inlet of a vane trailing edge cooling circuit, thereby increasing turbine efficiency via reduced cooling air flow requirements, while allowing an existing vane casting design to be used.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates generally to cooling of vanes in a combustion gas turbine and, more particularly, to a turbine vane which combines a thicker thermal barrier coating (TBC) with a cooling flow metering plate to maintain vane temperature within a specified range while improving efficiency of the turbine via reduced cooling air flow requirement, where the thicker TBC and the flow metering plate can be used with an existing vane design.

[0003] 2. Description of the Related Art

[0004] Combustion gas turbines are clean-burning, efficient devices for generating power for a variety of applications. One common application of combustion gas turbines is in power plants, where the turbine drives a generator which produces electricity. Such stationary gas turbines have been developed over the years to improve reliability and efficiency, but the continuous improvement quest never ends.

[0005] Turbines operate at very high temperature...

Examples

first embodiment

[0043]FIG. 9 is an illustration of a flow control insert device which can be placed into the trailing edge cooling passage inlet 140. Flow control insert 200 is, in one preferred embodiment, a thin strip of metal formed with a wavy shape. As shown in FIG. 9, the flow control insert 200 is shaped to fit down into the trailing edge cooling passage inlet 140, inside the trailing edge cooling passage 142, where it causes the cooling air flow to be directed against the walls 144 of the vane 100. Specifically, the insert 200 causes the cooling air flow to be directed against the walls on the pressure side 110 and the suction side 112 of the vane 100—not the interior-facing walls which separate the leading edge cooling passage 132 and the trailing edge cooling passage 142. The air flow acceleration and lateral velocity caused by the flow control insert 200 increases the convective heat transfer between the walls 144 and the cooling air, thus allowing a cooling air flow rate reduction while...

second embodiment

[0045]FIG. 10 is an illustration of a flow control insert device which can be placed into the trailing edge cooling passage inlet 140. Flow control insert 210 is, in one preferred embodiment, a thin strip of metal formed into a twisted shape. As shown in FIG. 10, the flow control insert210 is shaped to fit down into the trailing edge cooling passage inlet 140, inside the trailing edge cooling passage 142, where it causes the cooling air flow to swirl against the walls 144 of the vane 100. The flow control insert 210 offers the advantage of creating a swirling or twisting flow pattern in the cooling air which continues throughout the serpentine length of the trailing edge cooling passage 142. The swirling air flow motion caused by the flow control insert 210 increases the convective heat transfer between the walls 144 and the cooling air, thus allowing a cooling air flow rate reduction while maintaining vane temperature within specification. The insert 210 also serves as an obstructi...

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates generally to cooling of vanes in a combustion gas turbine and, more particularly, to a turbine vane which combines a thicker thermal barrier coating (TBC) with a cooling flow metering plate to maintain vane temperature within a specified range while improving efficiency of the turbine via reduced cooling air flow requirement, where the thicker TBC and the flow metering plate can be used with an existing vane design.

[0003] 2. Description of the Related Art

[0004] Combustion gas turbines are clean-burning, efficient devices for generating power for a variety of applications. One common application of combustion gas turbines is in power plants, where the turbine drives a generator which produces electricity. Such stationary gas turbines have been developed over the years to improve reliability and efficiency, but the continuous improvement quest never ends.

[0005] Turbines operate at very high temperature...

Examples

first embodiment

[0043]FIG. 9 is an illustration of a flow control insert device which can be placed into the trailing edge cooling passage inlet 140. Flow control insert 200 is, in one preferred embodiment, a thin strip of metal formed with a wavy shape. As shown in FIG. 9, the flow control insert 200 is shaped to fit down into the trailing edge cooling passage inlet 140, inside the trailing edge cooling passage 142, where it causes the cooling air flow to be directed against the walls 144 of the vane 100. Specifically, the insert 200 causes the cooling air flow to be directed against the walls on the pressure side 110 and the suction side 112 of the vane 100—not the interior-facing walls which separate the leading edge cooling passage 132 and the trailing edge cooling passage 142. The air flow acceleration and lateral velocity caused by the flow control insert 200 increases the convective heat transfer between the walls 144 and the cooling air, thus allowing a cooling air flow rate reduction while...

second embodiment

[0045]FIG. 10 is an illustration of a flow control insert device which can be placed into the trailing edge cooling passage inlet 140. Flow control insert 210 is, in one preferred embodiment, a thin strip of metal formed into a twisted shape. As shown in FIG. 10, the flow control insert210 is shaped to fit down into the trailing edge cooling passage inlet 140, inside the trailing edge cooling passage 142, where it causes the cooling air flow to swirl against the walls 144 of the vane 100. The flow control insert 210 offers the advantage of creating a swirling or twisting flow pattern in the cooling air which continues throughout the serpentine length of the trailing edge cooling passage 142. The swirling air flow motion caused by the flow control insert 210 increases the convective heat transfer between the walls 144 and the cooling air, thus allowing a cooling air flow rate reduction while maintaining vane temperature within specification. The insert 210 also serves as an obstructi...

Images